Comparison of Frequency Ratio and Certainty Factor Models in Badland Erosion Zonation (Case Study: Part of Jajrud Watershed)

Badland is final form of water erosion which has a lot of destructive effects in natural environmental. Southern slopes of central Alborz is exposed to badland erosion because of geomorphologic conditions. However, few studies have been conducted on badland erosion. The purpose of this study to compare efficiency of the frequency ratio model with certainty factor model in part of Jajrud watershed. To this purpose maps of effective factors including litho logy, elevation, slope, aspect and vegetation were digitized in ArcGIS. In the next stop, the frequency of the badland erosion in each class of factors was calculated through overlaying the dispersion map of badland erosion areas and the frequency ratio was achieved as result of it integration of those the zonation map was created using the frequency ratio and Certainty Factor models. Investigation into the efficiency of models show that model of frequency ratio and Certainty Factor with the empirical probability of 0.93 and 0.99, respectively are appropriate for badland erosion zonation. However, in comparison, the Certainty Factor model has a higher efficacy in the separation and recognition of appropriated areas for badland erosion zonation.